Endoscopic ligating instrument

ABSTRACT

An endoscopic instrument for ligating multiple lesions within a hollow body organ. A flexible endoscope 10 is provided with channels 16-21 for accomodating means for illumination, viewing and application of suction and is also provided with a hollow tubular member 101 affixed to the insertion end of the endoscope. A plurality of cords 103 are laid over the tube 101 to extend longitudinally thereon and be folded over the distal end of the tube. The cords 103 are connected to one another at a common point by a connector 106 inside the tube 101. A plurality of elastic rings 50 are mounted on the tube 101 in stretched condition and overlaying the cords 103. The segment of each cord 103 between each pair of adjacent rings 50 is in slack condition and of a length which equals or exceeds the distance of the tube&#39;s distal end to the furthest ring of the pair. By a trip cord 105 threaded through a working channel 19 of the endoscope and connected to the cords 103, a pull can be exerted thereon to simultaneously retract the cords 103 and dislodge each of the rings in controlled stepped sequence in a procedure wherein only one elastic ring at a time moves over the tube in the process of its dislodgement to ligate a lesion which has been suctioned part way into the tube 101.

This application is a continuation-in-part of application Ser. No.08/021036 filed Feb. 23, 1993, now U.S. Pat. No. 5,320,630.

FIELD OF THE INVENTION

The invention relates to an instrument for ligating lesions, and moreparticularly to an endoscopic instrument for ligating mucosal andsubmucosal lesions within a hollow organ of the body, such as thealimentary tract.

BACKGROUND ART

The endoscopic treatment of lesions presently encompasses a variety oftechniques such as electrocauterization, laser photocoagulation, heattherapy by the application of heat probes, and sclerotherapy whichinvolves the injection of medicine into a target varix by a needlepassed through the working channel of the endoscope. A further, widelyused and increasingly promising technique involves the ligation oflesions, wherein mucosal and submucosal tissue is strangulated by anelastic ligature.

A variety of instruments for effecting the ligation of body tissue bythe application of an elastic ring are well known in the prior art. Someof these instruments, because of their rigidity and size are suited onlyfor treatment of lesions that are in the external regions of the body orin the shallow body cavities. Others are particularly suited for theligation of tissue in the abdominal cavity, such as for tubal ligation,when the abdominal cavity has been opened surgically.

U.S. Pat. No. 3,760,810 to Van Hoorn discloses an endoscope-equippedinstrument comprising a device with two tubes mounted one inside theother, with the inner tube protruding at the front of the outer tube.Means are included to move the outer tube forwardly relative to theinner tube and cause an elastic cord to be dislodged and placed aboutthe tissue to be ligated. In U.S. Pat. No. 4,257,419, there is disclosedan instrument for ligating hemorrhoids wherein a suction tube fittedinside a proctoscope provides means for sucking the hemorrhoid into asuction cavity where a ligating ring is applied. Both of theseinstruments are rigid devices suited for treating lesions close to theexternal regions, and both are equipped with only a single elastic ringfor treating a single lesion.

There are also instruments in the prior art which employlaparoscope-assisted means for ring ligation such as shown in U.S. Pat.No. 4,257,420 and 4,471,766, wherein the instruments are each equippedwith a single elastic band and utilize forceps to position the tissuefor ring ligation.

In U.S. Pat. No. 3,870,048, there is disclosed a ring applicator devicehaving forceps slidably mounted in a cylinder for grasping the fallopiantube and including means for displacing an elastic ring to effect aligation of tissue. While this device can be equipped with a pluralityof elastic rings, it's rigidity precludes its use with a flexibleendoscope for treating the deeper regions of an internal organ, such asthe alimentary tract.

A flexible endoscopic instrument used for ligation purposes anddisclosed in U.S. Pat. No. 4,735,194 comprises a flexible fiberopticendoscope on the end of which is secured an outer tube and an inner tubereciprocally movable therein. A trip wire is fastened to the inner tubeto provide rearward motion to the inner tube to cause an elastic ringfitted about the inner tube to slide off and effect ligation. While thisinstrument is suitable for ligating lesions deep within the alimentarytract, it can only be used to treat but one lesion during a singleinsertion of the instrument.

In many instances, however, there are a number of lesions present in theorgan being treated, such as the esophagus, stomach or colon. If anendoscopic instrument equipped with only one elastic ring is used, thetreatment of multiple lesions in the same organ requires the extractionof the endoscope after the placing of each elastic ring about a lesionand reinsertion of the endoscope into the organ to repeat the procedurefor placing an elastic ligating ring about each of the lesions. Inaddition to being time consuming and an associated concern for bloodloss when there are bleeding lesions, there are other disadvantagesassociated with the repetitions of this procedure. The instrument, whenwithdrawn from the body, is usually covered with blood and mucous.Furthermore, each time the instrument is reinserted into the organ, itbecomes necessary to relocate a lesion to be treated and to orient theinstrument with respect thereto. In some cases where considerable bloodand mucous are present, the relocating of the instrument is a tediousand difficult task.

SUMMARY OF THE INVENTION

A flexible endoscopic instrument is provided with a plurality of elasticligating rings mounted on one tube of a pair of tubular members whichare affixed in coaxial relation to the insertion end of an endoscope.The rings are adapted to be dislodged therefrom in sequence atselectively controlled times for treating multiple lesions during asingle insertion of the endoscope into a body organ. The endoscope isequipped with illumination and viewing means to facilitate orientationof the instrument in the body organ, and longitudinally extendingtubular passages comprising a channel through which objects may bepassed and suction applied for drawing the lesion tissue into thetubular end of the endoscope to facilitate ligation of a lesion, and aworking channel through which a flexible actuating cable is inserted.The cable is connected to one of the tubular members and serves as ameans for imparting relative motion between the pair of tubular membersto sequentially dislodge the elastic rings from the endoscope atcontrolled times. Each of the elastic rings can be dislodged from theendoscope and placed in ligating relation to a lesion when lesion tissueis drawn into the innermost of the tubular members by a suction forceapplied through the suction channel and each of the rings can be appliedto a different one of the multiple lesions in the body organ during asingle insertion of the endoscope.

In one embodiment of the invention, a tubular member is provided with ahelical groove in its inner wall and with means at one end for fittingthe tubular member onto the insertion end of the endoscope. A pluralityof elastic ligating rings are mounted in stretched condition about theperiphery of a second tubular member which, when inserted into the firsttubular member with a twisting motion, causes the greater part of eachof the elastic rings to be placed in a different one of the coils of thehelical groove. By a drive gear connection between the flexible cableand the inner tubular member, rotary motion of the cable is imparted tothe inner tubular member whereby the elastic rings are adapted to bedislodged one at a time to effect the ligation of multiple lesionsduring a single insertion of the endoscope.

In a second embodiment, a first rigid tubular member is fitted to theinsertion end of the endoscope in coaxial relation thereto. A secondtubular member of flexible material is placed on the rigid tubularmember with a first outer portion thereof sleeved over the rigid tubularmember and a second portion inserted within the first tubular member byfolding over the free end of the rigid tubular member. The elastic ringsare placed in stretched condition about the outer portion of theflexible tubular member in side-by-side spaced relation to one another.By direct connection of the flexible cable to the inner second portionof the flexible tubular member, the cable can be retracted to pull mostof the outer sleeve portion over the free end of the rigid tube and intothe interior of the rigid tubular member thereby causing the elasticrings to be dislodged from the endoscope one at a time as they pass overthe end of the rigid tubular member at times controlled by theretraction of the flexible cable.

In a third embodiment, a rigid tubular member is fitted to the insertionend of the endoscope and a plurality of cords connected together at thesame point inside the tube, are each folded over its distal end with thefree end portion thereof extending in the longitudinal direction of thetube and angularly spaced relative to one another with respect to theaxis of the tube. A plurality of elastic rings are placed in stretchedcondition about the tube at longitudinally spaced locations thereon andalso over the cords which lay over the tube. Each cord is provided withknots at predetermined spaced locations thereon against each of which anelastic ring is placed. By means of a trip wire or trip line threadedthrough a working channel of the endoscope and connecting to the cordsat this mutual connecting point, the cords can be simultaneouslyretracted to pull the rings over the distal end of the tube incontrolled sequence. By also providing a slack length of the cordbetween each pair of adjacent elastic rings, which slack length equalsor exceeds the distance of the tube's distal end to the furthermost ringof the pair, a small pulling force is required to dislodge a ring fromthe tube.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal view, partly in section, of an endoscopicligating instrument representing a preferred embodiment of theinvention;

FIG. 2 is a frontal plan view of the insertion end of the endoscopicligating instrument of FIG. 1:

FIG. 3 is a section view through the end portion of the instrument astaken along the section line 3--3 in FIG. 2;

FIG. 4 is a fragmentary view in cross section showing details of the endportion of the flexible actuating cable at its connection with aplanetary gear in a tubular member in an assembly of tubular membersaffixed to the insertion end of the endoscope;

FIG. 5 is a section view through the insertion end of the endoscope astaken along the section line 5--5 in FIG. 3;

FIG. 6 is an exploded view of a tubular assembly which is affixed to theinsertion end of the endoscope;

FIG. 7 is a fragmentary view, partly in section, showing the insertionend of the instrument of the invention applied to a lesion with lesiontissue drawn by suction into an inner tubular member on the end of theinstrument;

FIG. 8 is a view similar to FIG. 7 but showing an elastic ligating ringapplied about a lesion after its dislodgement from the end of theendoscopic instrument of the invention;

FIG. 9 shows a lesion with an elastic ligating ring applied instrangulating relationship hereto;

FIG. 10 is a block plan view showing an endoscopic instrument as shownin FIG. 1 which is provided with a step-motor for selectively andautomatically controlling the rotation of the flexible cable;

FIG. 11 is a fragmentary view in longitudinal cross-section of amodified form of tubular assembly which is connectable to the insertionend of the endoscope of the invention;

FIG. 12 is a sectional view as taken along the section line 12--12 inFIG. 11;

FIG. 13 is an enlarged fragmentary view of the tubular assembly of FIG.11 which shows the nature and direction of the relative movement whichis imposed between the paired tubular members of the assembly foreffecting the discharge of an elastic ligating ring;

FIG. 14 is a view similar to FIG. 13 but showing a modified form ofribbing which is provided on the exterior of a textile member of thetubular assembly of FIG. 11;

FIG. 15 is a plan view of an embodiment of the invention as illustratedin FIGS. 11 through 14;

FIG. 16 is a perspective fragmentary view of a further embodiment of theinvention showing the insertion end of an endoscope with elastic ringsdisplaceably mounted on a rigid tube affixed thereto;

FIG. 17 is a front view of the apparatus attached to the insertion endof the endoscope of FIG. 16;

FIG. 18 is a longitudinal sectional view of the endoscope apparatus astaken along the section line 18--18 in FIG. 17 showing the arrangementof elastic rings on the rigid tube connected to the end of theendoscope;

FIG. 19 is an enlarged fragmentary view showing the distal end of thetubular member fitted to the end of the endoscope in FIG. 16; and

FIG. 20 is a longitudinal sectional view similar to FIG. 18 but showinga suctioned lesion ligated by an elastic ring which has been dislodgedfrom the tube.

DETAILED DESCRIPTION OF THE INVENTION

Referring more particularly to the drawings, there is shown in FIG. 1 aflexible endoscopic instrument 10 of a length which permits access tothe deeper regions of a hollow body organ, such as the alimentary tract.The instrument 10 comprises a conventional endoscope with an operatingcontrols section 11 of rigid construction and a flexible section 12which extends therefrom and is of a length sufficient to reach thedeeper regions of the alimentary tract. The distal end of the flexiblesection 12 is the insertion end 13 of the endoscope and the viewing end14 of the endoscope is at the end of the rigid operating controlssection 11 remote from the end thereof which connects to the flexiblesection 12.

The endoscope is provided with passages 16-21 which extendlongitudinally therein from its insertion end 13 to exit ports near theviewing end 14 of the endoscope. The passages comprise an illuminationchannel 16 through which is inserted a fiber optic cable for thetransmission of light from a light source, a viewing channel 17 which isalso provided with a fiber optic cable for viewing purposes, and achannel through which objects may be passed or suction applied 18. Theillumination channel and suction channel exit laterally through alateral extension 22 of the side wall of the endoscope at a location onthe operating controls section 11 near the viewing end 14. At their exitlocation, the fiber optic cable from channel 16 and the channel 18 areconnectable through an umbilical cable 23 to a control device (notshown) which is adaptable for supplying illumination to the transmissionoptic cable and for connecting the channel 18 to an appropriate meansfor applying a suction therethrough. The fiber optic viewing channel 17extends to the viewing end 14 of the endoscope which may be providedwith a viewing lens and an adapter for mounting a camera thereon, ifdesired.

The endoscope is also provided with a working channel 19 which extendsthrough the endoscope from its insertion end 11 to an exit in thelateral extension 22. The working channel 19 includes a branch 19a whichextends through an angularly extending protuberance 24 to a second exitnear the viewing end of the endoscope.

Additional channels 20 and 21, shown in FIG. 2, may be utilized fordelivering pressurized air or a jet stream of water for cleaning thelens.

In the embodiment of the invention shown in FIGS. 1 through 6, theinsertion end of the endoscope is fitted with an assembly of coaxiallyarranged tubes 25, 26, the outer tube 26 of which is secured in coaxialrelation thereto preferably by a tubular adapter 27 which provides afriction fit as shown in FIG. 3 although other fastening means such as athreaded connection might be suitably employed. The tube 26 ispreferably of transparent plastic material for enhancing theillumination and field of vision from the insertion end of theendoscope, although other inert material might also be suitableincluding stainless steel. The tube 26 is provided at its attaching endwith an external frusto-conical bevel surface 28 to facilitate theplacement of the tubular adapter 27 thereover. The adapter 27 ispreferably of a flexible material such as plastic and is provided withan internal diameter which allows it to be sleeved tightly over the tube26. For further enhancing the connection, the adapter 27 is providedwith an internal annular flange 31 which is adapted to seat in anaccommodating annular groove 32 formed externally about the surface ofthe tube 26, thereby locking the adapter 27 to the tube 26.

At its other end, the inner wall of the adapter 27 is formed with asuccession of outwardly diverging frusto-conical grooved surfaces 34which provide teeth-like edges for enhancing its grip on the endoscopewhen sleeved over the end thereof. In addition, it is provided with aninternal annular latching flange 36 which is adapted to seat in alatching groove 37 formed about the exterior of the endoscope.

The inner wall of outer tube 26 is formed with a helical groove 40 whichextends from its distal end for the greater part of its length. Near itsattaching end, the inner wall of outer tube 26 is formed with aninternal annular flange 41.

The inner tubular member 25 has a forward end 42 and a rearward end 43and comprises a first elongate section 44 and an adjoining shortersection 45 of circular cylinder configuration and larger radialdimensions. The tubular member 25 has an external annular shoulder 46formed at the junction of the elongate tubular section 44 with thelarger diameter section 45. The tubular member 25 is also provided aninternal annular radial shoulder 47, which is formed at the junction ofthe bore of section 45 with the smaller bore of the elongate section 44.

The elongate section 44 has a radial cross section in the configurationof a segmented circle and an external cylindrical surface characterizedby an elongate planar surface section 48 which extends from the forwardend 42 of the tubular member 25 to the radial shoulder 46.

The inner tubular member 25 serves as a carrier for a plurality ofelastic ligating rings 50 which are placed in stretched condition aboutthe elongate section 44 and mounted thereon in side-by-side relation toone another and in sleeved relation to the section 44. The elastic rings50 are typically of rubber material or an inert non-toxic plasticcomposition.

The tubular member 25 is also provided with a circular planetary gear 52which is seated in the bore of the circular section 45 in the coaxialrelation therewith. The gear 52 may be fabricated as an integral part ofthe tubular member 25 or it could be separately formed and bonded to theradial shoulder 47 and the inner cylindrical wall of circular section 45by an appropriate adhesive although other fastening means could also beused. An opening 49 is also provided in the radial shoulder 47 to insurefull communication of the interiors of the tubular members 25 and 26with the suction channel 18.

When completely assembled as shown in FIG. 3, the gear teeth ofplanetary gear 52 are in meshing engagement with a drive gear 53 whichis mounted by a connecting adapter 54 on the end of a flexible steelcable 55, preferably a single wire, which is inserted through theworking channel 19 of the endoscope. The cable 55 extends through theworking channel section 19a where it is fitted with a rotary controlmeans such as a knob 56 for manually effecting axial rotation of thecable 55.

The adapter 54 comprises a shaft 57 enlarged at one end which isprovided with a socket 58 characterized by a socket cavity ofrectangular transverse cross section which receives the squared end ofthe cable 55. At its other end, the shaft 57 is journalled for rotationon a transverse support 60 fitted internally of tube 25. The shaft 57 isalso fitted with a drive gear 53 which is fixed on the shaft 57 incoaxial relation thereto by a press fit or any suitable bonding means.Also sleeved about the shaft 57 is a plastic spacer 59 which is inabutting engagement with the drive gear 53 and one end of the socket 58.

Also shown in FIG. 3, a retaining ring 61 is also fitted into the end ofthe inner tubular member 25 in coaxial relation therewith and inabutting engagement with both the rearward end of the tubular member 25and the planetary gear 52. The retaining ring 61 is provided in itsouter surface with a circumferential groove 62 which receives theannular flange 41 of the tubular member 25 and latches the retainingring 61 in position.

In assembly of the instrument 10 the elastic ligating rings 50 must beplaced onto the inner tubular member 25 before it is inserted in theouter tubular member 26. This is also done before the tubular members25, 26 are fitted onto the endoscope. The elastic ligating rings 50,when in the relaxed state are of a diameter less than that of theinsertion end of the endoscope, which for representative endoscopes, isin the range of approximately 9 mm. to 13 mm. The rings 50 are placed instretched condition onto the elongate section 44 of the tubular member25 in side-by-side relation to one another and in sleeved relation tothe section 44. The tubular member 25 is then inserted with an axiallytwisting motion through the attaching end of the outer tubular member 26whereby each elastic ring, except for the portion thereof which restsatop the planar surface of the inner tubular member 25, is placed in acoil of the helical groove 40 in spaced relation to the adjacent elasticring in the next adjacent coil of the helical groove.

The tubular assembly, comprising tubular member 25 and 26 with tubularadapter 27 secured to the member 26, is then sleeved onto the insertionend of the endoscope such that the planetary gear 52 and drive gear 53are in meshed driving engagement with one another and the attaching endof the tubular member 26 abuts the insertion end of the endoscope.

When treating a patient, the endoscopic instrument of the invention isfirst inserted into the affected organ, such as the alimentary tract, toplace the insertion end of the endoscope in the vicinity of lesions inthe alimentary tract. In some instances, however, it may be preferredthat insertion of the instrument be preceded by the insertion of anendoscopic overtube (not shown) into the alimentary tract and theinstrument then be inserted through the overtube. In either case, theinstrument is then oriented for sighting of a target lesion, such aslesion 77 shown in FIG. 7, and the instrument advanced under the controlof a human operator until the distal end of the tubular member 25contacts the lesion area and is placed in surrounding relation to thetarget lesion.

A suction force is then applied through the suction channel 18 tocompletely draw the lesion tissue into the inner tubular member 25 asshown in FIG. 7. The operator then manually initiates axial rotation ofthe cable 55 and the inner tubular member 25 in the spirally forwarddirection of the helical groove 40 whereby the elastic rings 50 aredriven along the surface of the tubular member 25 by the walls of thehelical groove 40 until one of the elastic rings is dislodged from theinstrument and placed in ligating relation about the base of the targetlesion as shown in FIG. 8. The end of the instrument 10 is thenwithdrawn from around the lesion tissue, as shown in FIG. 9.

It is to be appreciated that by continuing the axial rotation of thetubular member 25, more of the elastic rings can be dislodged from theinstrument. Accordingly, the endoscopic instrument of the inventionpermits the successive ligation of multiple lesions during a singleinsertion of the instrument. With patients who are not bleeding, theligation treatment is started at the most distal point in the alimentarytract and then continued proximally so that elastic bands which areplaced about lesion tissue are not disturbed by movement of theinstrument. The instrument therefore facilitates the treatment ofmultiple lesions and alleviates the need for repeated removal andreinsertion of the instrument and reloading of an elastic ring fortreating each lesion.

In some instances, particularly where vision is obscured, the instrumentoperator may have difficulty in ascertaining the precise amount ofrotation of the flexible cable 55 that is necessary for dislodging oneand only one elastic ring 50 when ligating a single target lesion. Inthis respect, a modified form of the invention, which enables the axialrotation of the cable 55 in steps of precise amounts, is represented bythe endoscopic instrument 70 as shown in schematic form in FIG. 10. Theinstrument 70 is identical in all respects to the instrument 10 exceptfor the means of imparting axial rotation to the flexible cable 55 andidentical components are identically numbered. In lieu of a knob 56which enables the manual rotation of the cable 55, the instrument 70 isprovided with automatic means represented by a stepping motor 72 and acontroller 74 for rotation of the cable 55 in precisely controlledamounts. The controller 74 and motor 72 are connected to receive powerfrom an electrical power source 76. A foot pedal trigger switch 75 isused by the operator to energize the stepping motor 72 for a precisetime interval during which time the flexible cable 55 is axially rotatedby an amount which moves the elastic rings a precise distance along thetubular member 25 such that the most distal elastic ring 50 is forcedoff the end of the tubular member 25 and the remaining rings 50 areretained thereon. In effect, the precise time interval of motoroperation moves the elastic rings a distance which corresponds to thedistance between adjacent coils of the helical groove 40.

It is to be appreciated therefore that the endoscopic instrument 70provides the operator with means for precisely controlling when anelastic ring 50 is dislodged from the instrument and for insuring thatonly one elastic ring is dislodged when ligating a target lesion. It istherefore possible for the operator to dislodge additional elastic ringsin sequence and at times controlled by the operator so that multiplelesions can be ligated during a single insertion of the instrument.

A further embodiment of the invention represented by the endoscopicinstrument 80 is disclosed in FIGS. 11 through 15. The endoscopicinstrument 80 differs from the instruments 10 and 70 in the nature andoperation of the tubular assembly which is affixed to the insertion endof the endoscope, but is otherwise identical thereto. As shown in FIG.11, a rigid tube 81 is fixed in coaxial relation to the insertion end ofthe endoscope, preferably by a sleeve adapter 82. A tubular textilemember 83 of an inelastic material, such as the commercial productKevlar or other inelastic flexible material, is mounted onto the rigidtube 81 such that the member 83 is folded over the distal end of thetube 81 with a first portion 83a thereof being sleeved over the tube 81and a second portion 83b thereof disposed internally of the tube 81 andsubstantially coaxial thereto.

As shown in FIG. 11, a plurality of elastic ligating rings 50a areplaced in stretched condition in encircling relation about the portion83a of the tubular member 83. The textile material of portion 83a isprovided with an external surface having a plurality of annular ridges84 in the encircling relation thereto and preferably arranged in pairswhich define a plurality of uniformly spaced annular recesses or grooves85, each of which is adapted to receive an elastic ring 50a therein. Theelastic rings 50a are therefore maintained in uniform side-by-sidespacing on the tubular portion 83a.

The end of the second portion 83b of the textile tubular member 83 isfitted with a rigid annular ring clamping assembly 86 to which thetextile fabric of the tubular member 83 is attached. The clampingassembly 86 comprises an outer retaining ring 86a and an inner clampingring 86b which is of a smaller external diameter than the internaldiameter of the outer ring 86a and is insertable therein from the distalend of the tube 81 to clamp the portion 83b of the textile tubularmember 83 therebetween. Preferably, the inner wall of the outer ring 86ais formed with an annular coaxial groove 87 and the outer wall of theinner ring 86b is formed with an annular ridge 88 of conformingconfiguration and location such as to serve in retaining the textilemember 83 therebetween. The outer ring 86a is also provided with atleast three centering protuberances 90 which are in uniform angularspacing and serve to maintain the ring 86a in coaxial relation to thetube 81 and in a tight friction fit therein.

As best seen in FIG. 11, the adapter 82 is sleeved over an annular bevelsurface 89 on the attaching end of the tube 81 and is provided with aninternal annular flange 91 which latches in an annular groove 92 formedabout the external surface of the rigid tube 81. At its other end, theadapter is designed for a press fit connection with the insertion end ofthe endoscope as provided for the adapter 27 in the embodiment of FIG. 1or could be provided with threads, if desired.

A flexible cable 55a, similar to the cable 55 shown in the embodiment ofFIG. 1, and similarly threaded through the working channel of theendoscope is attached to an internal flange 93 on the inner wall of theclamping ring 86b. As best seen in FIGS. 11 and 12, one end of the cable55a is placed in an axial blind bore formed inwardly from one end of asleeve member 94 which is swaged in engagement therewith. The sleevemember 94 which is externally threaded at its other end, is insertedthrough an opening in the flange 93 and secured by a nut 95 on itsthreaded end. It is thus to be seen that by a pull on the cable 55a tothe right as shown in FIG. 11, the portion 83b of textile tubular member83 which is interior of the rigid tube 81 is increased and the portion83a which is exterior of the tube 81 is decreased.

The relative movement of the flexible tube 83 with respect to the rigidtube 81 is illustrated by arrows in FIG. 13 which show the textiletubular member 83 sliding over the distal end of the tube 81. As thismovement increases, the most distal of the elastic ligating rings 50apasses over the distal end of the tube 81 and is discharged therefrom.When the assembly of tubes 81, 83 are placed in surrounding relation toa target lesion, and lesion tissue is drawn into the tube 83 by suctionin a manner as previously described, it is to be appreciated thatligation of a lesion as shown in FIG. 9 can be readily achieved.

It is important that only a single ligating ring 50a be discharged fromthe instrument 80 for treating each lesion and the movement of the cable50a must be determined accordingly. After treating one lesion, theinstrument can be reoriented in surrounding relation to another lesionand the procedure repeated. Accordingly, multiple lesions can be ligatedduring a single insertion of the instrument. For most applications, theinstrument should be provided with at least six elastic rings 50a.

In FIG. 15, the cable 55a is shown attached to a reel 96 whereby anindexed rotation thereof is designed to move the cable 55a apredetermined distance to cause the discharge of only a single ligatingring 50a. Obviously, the movement could be controlled manually or othertechniques employed for controlling a precise axial movement of thecable 55a.

A variation in the arrangement of ridges 84 on the external surface ofthe textile tubular member 83 is shown in FIG. 14. In this modified formof the member 83, only a single ridge 84 is used for aligning theelastic rings 50a in uniform spacing on the member 83. The rings 50a areinstalled whereby each is in abutting engagement with the side of aridge 84 which faces toward the distal end of the tubular assembly so asto prevent their being moved or disturbed as the instrument is insertedinto a body organ.

It is to be noted that in the embodiment of the invention disclosed inFIGS. 11 through 15, the force required to pull the sleeve member 83over the distal end of the tube 81 increases proportionately with thenumber of elastic rings, such that a strong and sturdy construction mustbe used for the parts mounted on the insertion end of the endoscope andthe component parts for imparting sliding movement between the sleeve 83and the tube 81 and for a precise amount of sliding to ensure that onlyone ring is dislodged at a time. The force to dislodge the first ring,which must be strong enough to pull the sleeve and all the elastic ringstowards the distal end of the tube, is considerably greater than theforce required to dislodge the last remaining elastic ring from thetube.

A third embodiment of the invention represented by the endoscopicinstrument 100 disclosed in FIGS. 16 through 19 requires a pulling forceto dislodge an elastic ring which is comparable to that required fordislodging the last ring of the sleeve version disclosed in FIGS. 11through 15. As best seen in FIG. 16, a transparent rigid tube 101 isfitted to the insertion end of the endoscope 100 by an adapter section102 which provides a friction fit with the insertion end of theendoscope. The endoscope 100 is provided with a plurality of flexibleand substantially elastic cords 103, each of which is folded over thedistal end of the tube 101 and includes a first portion which is laidover the exterior surface of the tube and a second portion which isdisposed internally of the tube. The ends of the cords 103 inside thetube are fastened to one end of a flexible line 105 as by tying theretoor the use of an adapter connector 106. From its connection with cords103, the flexible line 105 is threaded through the working channel 19 ofthe endoscope and exits near the rearward end of the endoscope such thatthe exiting end portion of the line 105 may be fitted with a handle.

As best seen in FIG. 17, the cords 103 are disposed in preferablyuniform angular spacing about the longitudinal axis 107 of the tube 101.A plurality of elastic ligating rings 50 are each placed in stretchedcondition in sleeved relationship about the tube 101 and in overlyingrelation to the plurality of cords 103 to thereby hold the cords againstthe tube 101.

It is to be noted in FIGS. 16, 18 and 20 that the rings 50 are spacedfrom one another in the longitudinal direction of the tubular member atsuccesssingly greater distances from the distal end 108. Each cord 103is also provided with a series of longitudinally spaced knots 109against each of which an elastic ring 50 is placed on the forward sideof the knot. A means for imparting sliding motion between said cords andthe tubular member is provided by the flexible line element 105 by whichbecause of its connection to the ends of the cords 103 within thetubular member 101, a pulling force may be exerted at its outer end tocause sliding movement between the cords and the tubular member so as todislodge each of the elastic rings in desirably controlled sequence.When the pull is applied, a knot 109 acts as a shoulder which precludesrelative movement between the elastic ring and the cord until the ringis dislodged at the distal end of the tubular member.

As is best shown in FIG. 16, each cord 103 includes a segment of cordbetween each pair of adjacent elastic rings which is in slack conditionand of a length which is equal to the distance between said pair plusthe distance from the distal end of the tube 101 to the ring of the pairwhich is nearest the distal end 108. It will therefore be seen that whenthe cords are pulled a distance which moves the forward ring of the pairto the distal end of the tube and off the tube, the slack length of cordsuffices to preclude any movement of the remaining elastic rings. It istherefore to be noted that the required pulling force to dislodge a ringis that which is necessary to move a single ring and the required forcedoes not increase as additional rings are dislodged.

After the cords 103 and elastic rings 50 have been loaded on the rigidtube 101 and positioned thereon as shown in FIGS. 16 and 18, it may be adesirable option to place a flexible sleeve of plastic or a textilemateral to fit loosely over the cords 103 and the tube 101. Such asleeve, when attached at one end to the flexible section 12 of theendoscope and extending over the cords 103 and elastic rings 50 toapproximately the distal end of the tube 101, would serve to protectagainst "snagging" of the slack segments or loop of cords between therings when the endoscope is in use or prepared for use.

It is to be understood that the foregoing descriptions of a preferredembodiment of the invention has been presented for purposes ofillustration and explanation and are not intended to limit the inventionto the precise forms disclosed. For example, a motor control could beprovided for controlling the movement of the cable 55a in precise steps.Also, the number of elastic ligating rings 50 or 50a could be greater orless than those illustrated herein. In some instances the rings 50a canbe aligned on the textile tubular member 83 without ridges 84. It is tobe appreciated therefore, that various material and structural changesmay be made by those skilled in the art without departing from thespirit of the invention.

I claim:
 1. A flexible endoscopic instrument for ligating a multiplicityof lesions within a hollow body organ, such as the alimentary tract,said instrument comprising:(a) a flexible fiber optic endoscope having aforward insertion end and a rearward end, said endoscope including meansfor illumination and viewing through said endoscope, means for providinga suction force at said insertion end, and a working channel; (b) atubular member having a forward distal end, a rearward end and alongitudinal axis, said rearward end having means for providingattachment to the insertion end of the endoscope; (c) a plurality ofstring-like cords of flexible substantially inelastic material, eachsaid cord being folded over the distal end of the tubular member with afirst portion of each said cord overlaying a part of the exterior ofsaid tubular member and a second portion thereof being disposedinternally of said tubular member, said cords being oriented in angularspacing about the longitudinal axis of said tubular member; (d) aplurality of elastic ligating rings removably mounted in stretchedcondition on said tubular member in coaxial relation thereto and each ofsaid rings being in overlying contacting relation to all of saidplurality of cords, said rings being spaced from one another in thelongitudinal direction of the tubular member at successively greaterdifferent distances from the distal end of the tubular member; and (e)means for imparting relative sliding motion between said cords and saidtubular member to dislodge each of the elastic rings in controlledsequence during a single insertion of the endoscope into the body organwhereby each of the elastic rings can be dislodged from the endoscopeand placed in ligating relation to a lesion when lesion tissue is drawninto the tubular member by said suction means with each ring beingapplied to a different one of multiple lesions present in the bodyorgan, said means for imparting relative sliding motion comprising aflexible line element threaded through the working channel of theendoscope and connecting at one end to said cords disposed within saidtubular member and exiting the endoscope at the rearward end thereofwhereby a pulling force may be exerted on the other end of the lineelement to cause sliding movement of the cords over said tubular member,each said cord being arranged in slack condition between each pair ofadjacent elastic rings.
 2. A flexible endoscopic instrument for ligatinga multiplicity of lesions within a hollow body organ, such as thealimentary tract, said instrument comprising:(a) a flexible fiber opticendoscope having a forward insertion end and a rearward end, saidendoscope including means for illumination and viewing through saidendoscope, means for providing a suction force at said insertion end,and a working channel; (b) a tubular member having a forward distal end,a rearward end and a longitudinal axis, said rearward end having meansfor providing attachment to the insertion end of the endoscope; (c) aplurality of string-like cords of flexible substantially inelasticmaterial, each said cord being folded over the distal end of the tubularmember with a first portion of each said cord overlaying a part of theexterior of said tubular member and a second portion thereof beingdisposed internally of said tubular member, said cords being oriented inangular spacing about the longitudinal axis of said tubular member; (d)a plurality of elastic ligating rings removably mounted in stretchedcondition on said tubular member in coaxial relation thereto and inoverlying relation to said cords, said rings being spaced from oneanother in the longitudinal direction of the tubular member and betweenat least one pair of adjacent elastic rings each of said cords having aslack segment of cord of a length which is at least equal to thedistance between the distal end of the tubular member and the ring ofsaid pair which is furthest from said distal end; and (e) means forimparting relative sliding motion between said cords and said tubularmember to dislodge each of the elastic rings in controlled sequenceduring a single insertion of the endoscope into the body organ wherebyeach of the elastic rings can be dislodged from the endoscope and placedin ligating relation to a lesion when lesion tissue is drawn into thetubular member by said suction means with each ring being applied to adifferent one of multiple lesions present in the body organ, said meansfor imparting relative sliding motion comprising a flexible line elementthreaded through the working channel of the endoscope and connecting atone end to said cords disposed within said tubular member and exitingthe endoscope at the rearward end thereof whereby a pulling force may beexerted on the other end of the line element to cause sliding movementof the cords over said tubular member, each said cord being arranged inslack condition between each pair of adjacent elastic rings.
 3. Anendoscopic ligating instrument as set forth in claim 2 wherein each saidcord on the portion thereof which overlies said rigid tubular memberincludes a series of shoulders at spaced intervals and against each ofwhich a different one of said elastic rings is placed in abuttingengagement and facing the distal end of said rigid tubular member andwherein each of said shoulders of a cord is in substantially co-planarrelationship with a shoulder of each of the other cords.
 4. Anendoscopic ligating instrument as set forth in claim 2 wherein each saidcord on the portion thereof which overlies said rigid tubular memberincludes a series of knots at spaced intervals and against each of whicha different one of said elastic rings is placed in abutting engagementand facing the distal end of said rigid tubular member and wherein eachof said knots of a cord is in substantially co-planar relationship witha knot of each of the other of said cords.
 5. A flexible endoscopicinstrument for ligating a multiplicity of lesions within a hollow bodyorgan, such as the alimentary tract, said instrument comprising:(a) aflexible fiber optic endoscope having a forward insertion end and arearward end, said endoscope including means for illumination andviewing through said endoscope, means for providing a suction force atsaid insertion end, and a working channel; (b) a tubular member having aforward distal end, a rearward end and a longitudinal axis, saidrearward end having means for providing attachment to the insertion endof the endoscope; (c) a plurality of string-like cords of flexiblesubstantially inelastic material, each said cord being folded over thedistal end of the tubular member with a first portion of each said cordoverlaying a part of the exterior of said tubular member and a secondportion thereof being disposed internally of said tubular member, saidcords being oriented in angular spacing about the longitudinal axis ofsaid tubular member; (d) a plurality of elastic ligating rings removablymounted in stretched condition on said tubular member in coaxialrelation thereto and in overlying relation to said cords, said ringsbeing spaced from one another in the longitudinal direction of thetubular member at successively greater different distances from thedistal end of the tubular member, such that the length of each cordbetween each pair of adjacent elastic rings is at least equal to thedistance between the distal end of the tubular member and the furthestring of said pair from said distal end; and (e) means for impartingrelative sliding motion between said cords and said tubular member todislodge each of the elastic rings in controlled sequence during asingle insertion of the endoscope into the body organ whereby each ofthe elastic rings can be dislodged from the endoscope and placed inligating relation to a lesion when lesion tissue is drawn into thetubular member by said suction means with each ring being applied to adifferent one of multiple lesions present in the body organ, said meansfor imparting relative sliding motion comprising a flexible line elementthreaded through the working channel of the endoscope and connecting atone end to said cords disposed within said tubular member and exitingthe endoscope at the rearward end thereof whereby a pulling force may beexerted on the other end of the line element to cause sliding movementof the cords over said tubular member, each said cord being arranged inslack condition between each pair of adjacent elastic rings.
 6. Anendoscopic ligating instrument as set forth in claim 5 wherein each saidcord on the portion thereof which overlies said rigid tubular memberincludes a series of radially extending shoulders at spaced intervalsand against each of which a different one of said elastic rings isplaced in abutting engagement and facing the distal end of said rigidtubular member and wherein each of said shoulders of a cord is insubstantially co-planar relationship with a shoulder of each of theother cords.
 7. An endoscopic ligating instrument as set forth in claim5 wherein each said cord on the portion thereof which overlies saidrigid tubular member includes a series of knots at spaced intervals andagainst each of which a different one of said elastic rings is placed inabutting engagement and facing the distal end of said rigid tubularmember and wherein each of said knots of a cord is in substantiallyco-planar relationship with a knot of each of the other of said cords.